﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CheckTTS
{
    public partial class EditControl : UserControl
    {
        public EditControl()
        {
            InitializeComponent();
        }

        private void richTextBox_Main_TextChanged(object sender, EventArgs e)
        {
            updateLabelRowIndex();
        }

        private void richTextBox_Main_FontChanged(object sender, EventArgs e)
        {
            updateLabelRowIndex();
            richTextBoxMain_VScroll(null, null);
        }

        private void richTextBox_Main_Resize(object sender, EventArgs e)
        {
            richTextBoxMain_VScroll(null, null);
        }

        private void richTextBoxMain_VScroll(object sender, EventArgs e)
        {
            //move location of numberLabel for amount of pixels caused by scrollbar
            int p = richTextBoxMain.GetPositionFromCharIndex(0).Y % (richTextBoxMain.Font.Height + 1);
            labelRowIndex.Location = new Point(0, p);
            updateLabelRowIndex();
        }

        public void setText(string path)
        {

            richTextBoxMain.LoadFile(path, RichTextBoxStreamType.PlainText);
        }

        private void updateLabelRowIndex()
        {
            //we get index of first visible char and number of first visible line
            Point pos = new Point(0, 0);
            int firstIndex = this.richTextBoxMain.GetCharIndexFromPosition(pos);
            int firstLine = this.richTextBoxMain.GetLineFromCharIndex(firstIndex);

            //now we get index of last visible char and number of last visible line
            pos.X += this.richTextBoxMain.ClientRectangle.Width;
            pos.Y += this.richTextBoxMain.ClientRectangle.Height;
            int lastIndex = this.richTextBoxMain.GetCharIndexFromPosition(pos);
            int lastLine = this.richTextBoxMain.GetLineFromCharIndex(lastIndex);

            //this is point position of last visible char,
            //we'll use its Y value for calculating numberLabel size
            pos = this.richTextBoxMain.GetPositionFromCharIndex(lastIndex);

            labelRowIndex.Text = "";
            for (int i = firstLine; i <= lastLine + 1; i++)
            {
                labelRowIndex.Text += i + 1 + "\r\n";
            }
        }
    }
}
